System and method for faulting to return air sensor

ABSTRACT

A system faults to a return air sensor integrated within a heating, ventilation, and air conditioning (HVAC) unit. The system transmits a signal to a remote sensor. The system determines that a return signal is not received from the remote sensor. The system obtains a temperature reading from the return air sensor. The system determines whether the temperature reading satisfies a temperature setting stored in the memory. In response to determining that the temperature reading does not satisfy the temperature setting, the system enables heating or cooling of the HVAC unit until the temperature setting is satisfied. In response to determining that the temperature reading satisfies the temperature setting, the system disables heating or cooling of the HVAC unit.

CROSS REFERENCE TO RELATED APPLICATION(S)

This application claims the benefit of U.S. Provisional Application Ser. No. 62/817,827, entitled “SYSTEM AND METHOD FOR FAULTING TO RETURN AIR SENSOR” and filed on Mar. 13, 2019, which is expressly incorporated by reference herein in its entirety.

FIELD

The present disclosure generally relates to control of heating, ventilation, and air conditioning (HVAC) systems, and more specifically to systems and methods for faulting to a return air temperature sensor.

BACKGROUND

Generally, HVAC systems rely on network connectivity and wireless or wired sensors to operate without a formal thermostat. Thus, an HVAC system can power up and power down based on readings from the sensors and user defined setpoint information for a temperature and/or a humidity level. Users can program setpoint information on their mobile devices via a user interface in many advanced HVAC systems. However, in some cases, the remote sensor may fail or the HVAC system may be unable to communicate with the sensor.

In this situation, the HVAC system must still continue to heat or cool the building (e.g., a house), but cannot operate without base information regarding the current conditions inside a particular building. In prior configurations, a thermostat provided conditioning information and allowed users to identify a setpoint. Furthermore, conventional thermostats were typically wired, so lost connections were rather uncommon. However, with the elimination of a thermostat, when network connectivity is lost, or communication with the remote sensors are lost, the HVAC system cannot function properly.

Therefore, there is a need for systems and methods that allow uninterrupted heating or cooling even in the event that one or more sensors within a building are unavailable.

SUMMARY

The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

The present disclosure provides temperature control systems, apparatuses, and methods.

In an aspect, a system for faulting to a return air sensor integrated within a heating, ventilation, and air conditioning (HVAC) unit includes a memory configured to store a set of instructions; and a processor coupled with the memory and configured to execute the instructions. The processor is configured to transmit a signal to a remote sensor. The processor is further configured to determine that a return signal is not received from the remote sensor. The processor is further configured to obtain a temperature reading from the return air sensor. The processor is further configured to determine whether the temperature reading satisfies a temperature setting stored in the memory. The processor is further configured to, in response to determining that the temperature reading does not satisfy the temperature setting, enable heating or cooling of the HVAC unit until the temperature setting is satisfied. The processor is further configured to, in response to determining that the temperature reading satisfies temperature setting, disable heating or cooling of the HVAC unit.

In another aspect, a method for faulting to a return air sensor integrated within a heating, ventilation, and air conditioning (HVAC) unit is provided. The method includes transmitting a signal to a remote sensor. The method further includes determining that a return signal is not received from the remote sensor. The method further includes obtaining a temperature reading from the return air sensor. The method further includes determining whether the temperature reading satisfies a temperature setting. The method further includes, in response to determining that the temperature reading does not satisfy the temperature setting, enabling heating or cooling of the HVAC unit until the temperature setting is satisfied. The method further includes, in response to determining that the temperature reading satisfies the temperature setting, disabling heating or cooling of the HVAC unit.

In a further aspect, a non-transitory computer-readable medium is provided. The non-transitory computer-readable medium stores instructions that, when executed by a processor, cause the processor to fault to a return air sensor integrated within a heating, ventilation, and air conditioning (HVAC) unit. The processor is configured to transmit a signal to a remote sensor. The processor is further configured to determine that a return signal is not received from the remote sensor. The processor is further configured to obtain a temperature reading from the return air sensor. The processor is further configured to determine whether the temperature reading satisfies a temperature setting. The processor is further configured to, in response to determining that the temperature reading does not satisfy the temperature setting, enabling heating or cooling of the HVAC unit until the temperature setting is satisfied. The processor is further configured to, in response to determining that the temperature reading satisfies the temperature setting, disabling heating or cooling of the HVAC unit.

To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed, and this description is intended to include all such aspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an example of an HVAC system according to aspects of the present disclosure.

FIG. 2 is a flow diagram for an example method of defaulting to a return air temperature sensor, according to aspects of the present disclosure.

FIG. 3 is a block diagram of an example controller according to aspects of the present disclosure.

FIG. 4 is a block diagram of an example mobile device according to aspects of the present disclosure.

DETAILED DESCRIPTION

Various aspects of the disclosure are now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to promote a thorough understanding of one or more aspects of the disclosure. It may be evident in some or all instances, however, that any aspects described below can be practiced without adopting the specific design details described below. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate description of one or more aspects. The following presents a simplified summary of one or more aspects of the disclosure in order to provide a basic understanding thereof.

Referring to FIG. 1, an HVAC system 100 for a building 10 is disclosed. The HVAC system 100 may include an HVAC unit 110 configured to control an ambient condition of the one or more rooms of the building 10 based on information from one or more sensors 150 and a remote user device 160. In an example, an ambient condition may be a temperature or a humidity level. As shown by FIG. 1, the HVAC unit 110 may be external to the building 10. In an aspect, one or more components (e.g., air conditioning (A/C) unit 112, furnace 114, blower 116, communications component 130, or controller 140) may be located in different locations including inside the building 10. The building may be a home, office or any other structure that includes uses an HVAC system for controlling one or more ambient conditions of the structure.

In an aspect, the HVAC system 100 may include supply ducts 120 and return ducts 124 installed within the building 10 and coupled with the HVAC unit 110. The supply ducts 120 may supply air to the building 10, and the return ducts 124 may return air from the building 10. The supply ducts 120 may receive supply air through one or more of intakes 128 that provide outside air to the HVAC system 100 and/or may recycle return air from the return ducts 124. The supply ducts 120 may output the supply air at one or more of the rooms of the building 10 via one or more supply vents 122. The return ducts 124 may receive return air from the building 10 via the return ducts 124 to balance air within the building 10. The return air may be input into the return ducts 124 via one or more return vents 126. In one aspect, one or more return air sensor(s) 125 may be located within the return air duct 124, external to the building 10, though in some configurations, the one or more return air sensor(s) 125 may be located in the building 10 within the return air duct 124 also. In FIG. 1, the return air sensor 125 is integrated within the HVAC unit 110, e.g., is located inside the return ducts 124 within the HVAC unit 110, but alternative locations are also contemplated herein. The return air sensor 125 measures the temperature or other settings such as humidity or the like of the air returning from the building 10 through the return duct 124.

The HVAC unit 110 may include one or more of an A/C unit 112, a furnace 114, a blower 116, a humidifier/dehumidifier 118, or any other component (e.g., heat pump, not shown) for adjusting an ambient condition of a room of the building 10. The A/C unit 112 may be configured to cool the supply air by passing the supply air through or around one or more cooled pipes (e.g., chiller pipes) to lower a temperature of the supply air. The furnace 114 may be configured to warm the supply air by passing the supply air through or around one or more warmed pipes (e.g., heating coils) to raise a temperature of the supply air. The blower 116 may be configured to blow the supply air through the supply ducts 120 to the building 10 and pull the return air from the building 10.

The HVAC unit 110 may also include a communications component 130 configured to communicate with the one or more sensors 150 and/or the remote user device 160. In an aspect, the communications component 130 may communicate with the one or more sensors 150 and/or the remote user device 160 via one or more communications links 132. In an example, the communications component 130 may include one or more antennas, processors, modems, radio frequency components, and/or circuitry for communicating with the sensor 150 and/or the remote user device 160. The one or more communications links 132 may be wired or wireless communication links.

The HVAC system 100 may also include the one or more sensors 150 located within one or more rooms of the building 10 and/or within or near the supply vents 122. One or more sensors 150 may be configured to detect an ambient condition such as a temperature or a humidity level of the room where the sensor 150 is located, or even occupancy of the room (using, e.g., optical beam interruption for recognizing movement or the like). Each of the sensors 150 may provide sensor information 131 to the HVAC unit 110. Examples of a sensor 150 may include a temperature sensor, a humidity sensor, or any sensor configured to detect an ambient condition of one or more rooms of the building 10.

The HVAC system 100 may also include the remote user device 160 configured to communicate with the HVAC unit 110. The remote user device 180 may include an HVAC application 162 configured to display, adjust, and store setpoint information (“info”) 164 indicating desired user settings for one or more rooms of the building 10. In an example, the setpoint information 164 may include temperature settings 166 indicating one or more desired temperatures (e.g., minimum and/or maximum room temperatures) for one or more rooms of the building and/or humidity settings 188 indicating a desired humidity level for one or more rooms of the building 10. The remote user device 160 may provide the setpoint information 164 to the HVAC unit 110. Examples of a remote user device 160 may include a mobile device, a cellular phone, a smart phone, a personal digital assistant (PDA), a smart speaker, a home assistant, a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless phone, a smart watch, an entertainment device, an Internet of Things (IoT) device, or any device capable of communicating with the HVAC unit 110. A smart speaker may include, for example, an Echo® device available from Amazon, Inc. of Seattle, Wash., a Google Home® device available from Google, Inc. of Mountain View, Calif., or other similar devices. The HVAC application 162 may include a voice interface that response to voice commands.

The HVAC unit 110 may also include a controller 140 configured to control the A/C unit 112, the furnace 114, and the blower 116 based on the sensor information 131 received from the one or more sensors 150 and the setpoint information 164 received from the remote user device 160. The controller may communicate with the communications component 130, the A/C unit 112, the furnace 114, and/or the blower 116 via a communications bus 134. The controller 140 may include logic to determine when to initiate the blower 116 along with one of the A/C unit 112 or the furnace 114 based on the sensor information 131 and the setpoint information 164. The controller 140 may also include logic to determine a time and/or a speed to run the blower 116 along with a time or power level to run one of the A/C unit 112 or the furnace 114 based on the sensor information 131 and the setpoint information 164.

The controller 140 may further comprise an operation control component 142 to perform the logic of the controller 140, the operation control component 142 comprising a monitoring component 144, a system initiator 146 and a sensor default component 152. The controller 140, in some instances, may be unable to communicate with the one or more remote sensor(s) 150. In this case, in order to continue uninterrupted operation of the HVAC unit 110, the controller 140 may rely on the sensor default component 152, a component of the operation control component 142 to default to reading temperatures from the return air sensor 125 for temperature and/or humidity readings. The sensor default component 152 determines whether a return signal is received from the one or more remote sensors 150, using for example, the monitoring component 144 that receives readings via the sensor information (“info”) receiver 148.

In some aspects, the controller 140 waits a predetermined period of time (e.g., approximately thirty seconds to one minute) with no communication prior to using the return air sensor 125 for temperature readings. In some aspects, the sensor default component 152 may flag the absence of a return signal from the one or more remote sensors 150 and issue a warning to a user of the HVAC unit 110 that communication is lost with the one or more remote sensors 150. The warning may be issued on a user interface 304 (shown in FIG. 3) associated with the HVAC unit, and/or sent as an alert to the user's mobile device(s) 160, using the communications component 130. Additionally, the warning may be displayed on the external warning indicator 302 (shown in FIG. 3) of the HVAC unit 110. In some aspects of the present disclosure, the warning or alert may be an email, text message or any other type of notification, for example a notification associated with an HVAC application 162 on the mobile device(s) 160.

In some aspects, the sensor default component 152 may use a comparer 149 to compare a reading obtained from the return air sensor 125 with the setpoint information 164. If the reading from the return air sensor 125 does not satisfy the temperature settings 166, the system initiator 146 will start or stop one or more components of the HVAC unit 110, e.g., the furnace 114, the A/C 112, the blower 116, etc., until the conditions specified in the temperature settings 166 are satisfied. If the reading from the return air sensor 125 is equal to or within the minimum and maximum temperature specified in the settings 166, the sensor default component 152 does not initiate the blower 116.

In one non-limiting aspect, for example, when the HVAC unit 110 is configured/set for providing heating functionality (e.g., during winter), if the reading from the return air sensor 125 is less than a corresponding minimum temperature setting specified in the temperature settings 166, the system initiator 146 may start the furnace 114 and the blower 116 to circulate heated air into the building 10 to reduce the reading returned from the return air sensor 125 to meet the temperature settings 166. For example, in an aspect, the system initiator 146 may operate the furnace 114 and the blower 116 until the reading from the return air sensor 125 is greater than or equal to a corresponding maximum temperature setting specified in the temperature settings 166.

In another non-limiting aspect, for example, when the HVAC unit 110 is configured/set for providing cooling functionality (e.g., during summer), if the reading from the return air sensor 125 is greater than a corresponding maximum temperature specified in the temperature settings 166, the system initiator 146 may start the A/C 112 and the blower 116 to circulate cooled air into the building 10 to reduce the reading returned from the return air sensor 125 to meet the temperature settings 166. For example, in an aspect, the system initiator 146 may operate the A/C 112 and the blower 116 until the reading from the return air sensor 125 is less than or equal to a corresponding minimum temperature setting specified in the temperature settings 166.

FIG. 3 shows further detail regarding the controller 140, including a user interface 304 along with a warning indicator 306 that is enabled when the monitoring component 144 determines that communication with the remote sensor(s) 150 is unavailable. Further, FIG. 3 illustrates that the controller 140 may include a processor 320 and memory 322, the memory 322 storing, for example, last setpoint information 330 in case network communication is lost along with stage setting(s) 340 that control various stages of operation of the HVAC unit 110 if it is a multi-stage unit. Further detail regarding the implementation of controller 140 is shown in FIG. 5.

FIG. 2 is a flow diagram for a method 200 for defaulting to a return air sensor by the HVAC unit 110, where the return air sensor is integrated within the HVAC unit 110, in accordance with some aspects of the present disclosure. The method 200 may implement the functionality described herein with reference to FIG. 1 and may be performed by one or more components of the HVAC unit 110 as described herein with reference FIGS. 1 and 3.

The method 200 begins at 202, where the method 200 may include determining whether a network connection is available to the network the HVAC unit 110 may connect to. If the connection is available, the method 200 proceeds to 204. However, if it is detected that the connection is unavailable, the method 200 proceeds to 208, described below, where the return air sensor is used to control the HVAC unit. For example, one or more components (e.g., controller 140, processor 320, operation controller 142 or monitoring component 144) of the HVAC unit 110 may determine whether the network connection is available or unavailable.

At 204, the method 200 may also include transmitting a signal to one or more of the remote sensors 150. For example, one or more components (e.g., controller 140, processor 320, operation controller 142 or monitoring component 144) of the HVAC unit 110 may transmit the signal to one or more remote sensors 150.

At 206, the method 200 may also include determining that a return signal is not received from the one or more remote sensors 150. For example, one or more components (e.g., controller 140, processor 320, operation controller 142 or monitoring component 144) of the HVAC unit 110 may determine that the return signal is not received. In some aspects, the component waits a predetermined period of time (e.g., thirty seconds to one minute, though this is configurable or preset) prior to continuing with method 200. In some aspects, the component may flag the absence of a return signal from the one or more remote sensors 150 and issue a warning to a user of the HVAC unit 110 that communication is lost with the one or more remote sensors 150. The warning may be issued on a user interface 304 associated with the HVAC unit, and/or sent as a notification to the user's mobile device(s) 160. Additionally, the warning may be displayed on the external warning indicator 302 of the HVAC unit 110. In some aspects of the present disclosure, the warning may be an email, text message or any other type of notification, for example a notification associated with an HVAC application 162 on the mobile device(s) 160.

At 208, the method 200 may also include obtaining a temperature reading from a return air temperature sensor (e.g., return air sensor 125 integrated within the HVAC unit 110 as shown in FIG. 1) as a value representative of the temperature inside the house. For example, one or more components (e.g., controller 140, processor 320, operation controller 142 or monitoring component 144) of the HVAC unit 110 may obtain the temperature reading from the return air sensor 125. In some aspects, a significant amount of time may have passed since the blower 116 of the HVAC unit 110 has been off. Therefore readings from the return air sensor 125 may not be fully representative of the air temperature inside the building 10. Further, the return air sensor 125 may be located external to the building 10 and may be influenced by external temperatures. Therefore, in this aspect, prior to obtaining a reading from the return air sensor 125, the component may determine that the HVAC unit 110 is in an off cycle (e.g., the blower 116 is off) for a predetermined period of time and enable one or more fans of the blower 116 of the HVAC unit 110 to circulate air from the respect unit into the building 10 by powering up the blower 116. In some aspects, the air may be recirculated for a predetermined period of time. Then, when several cycles of air have flowed in and returned to the HVAC unit 110 via the return air duct 124 (i.e., circulated) or a predetermined amount of time has passed (e.g., five minutes), readings from the return air sensor 125 may be significantly more representative of temperatures inside the building 10. Thus, after the air circulates for several cycles, the component may then obtain a temperature reading from the return air sensor 125 before continuing with the method 200.

At 210, the method 200 may also include determining whether the obtained readings satisfy a temperature setting specified in the last setpoint information 330 stored in the memory 322 of the controller 140. For example, one or more components (e.g., controller 140, processor 320, operation controller 142 or monitoring component 144) of the HVAC unit 110 may compare the obtained temperature with a last setpoint information 330 stored in the controller 140. In some aspects, the temperature outside of the house may be significantly different than the temperature inside of the house and may affect the return air sensor 125 that is generally also located outside the building 10 within the return air duct 124 near the HVAC unit 110. In this instance, it may be advantageous to, prior to comparing the obtained temperature, obtain ambient temperature information if it is available. For example, ambient temperature information may be obtained by ambient air temperature sensors (not shown) located outside the HVAC unit 110 or elsewhere outside the building 10. In other aspects, external temperature information may be obtained through the Internet through a weather service or the like. Once the external temperature is received, the reading obtained from the return air sensor 125 may be offset by the external temperature reading.

If at 210, the reading from the return air sensor 125 is equal to or within the minimum and maximum temperatures specified in the temperature settings 166, the sensor default component 152 does not initiate the blower 116 and the method 200 returns to 202. However, in response to determining that the obtained reading does not satisfy the conditions specified in the temperature settings 166, the method 200 proceeds to 212.

At 212, the method 200 may also include enabling heating or cooling of the HVAC unit 110. For example, one or more components (e.g., controller 140, processor 320, operation controller 142 or monitoring component 144) of the HVAC unit 110 may enable the heating or cooling of the HVAC unit 110, as described above with reference to FIG. 1. For example, in one non-limiting aspect, when the HVAC unit 110 is configured/set for providing heating functionality (e.g., during winter), if the reading from the return air sensor 125 is less than a corresponding minimum temperature setting specified in the temperature settings 166, the system initiator 146 may start the furnace 114 and the blower 116 to circulate heated air into the building 10 until the reading returned from the return air sensor 125 meets the temperature settings 166. For example, in an aspect, the system initiator 146 may operate the furnace 114 and the blower 116 until the reading from the return air sensor 125 is greater than or equal to a corresponding maximum temperature setting specified in the temperature settings 166. In another non-limiting aspect, for example, when the HVAC unit 110 is configured/set for providing cooling functionality (e.g., during summer), if the reading from the return air sensor 125 is greater than a corresponding maximum temperature setting specified in the temperature settings 166, the system initiator 146 may start the A/C 112 and the blower 116 to circulate cooled air into the building 10 until the reading returned from the return air sensor 125 meets the temperature settings 166. For example, in an aspect, the system initiator 146 may operate the A/C 112 and the blower 116 until the reading from the return air sensor 125 is less than or equal to a corresponding minimum temperature setting specified in the temperature settings 166.

Once the reading from the return sensor 125 comes within a particular threshold value of the temperature settings 166, the method 200 may return to 202, operating periodically until return signals are received.

Though not shown in FIG. 3, after the setpoint in the setpoint information 164 is reached, the controller 140 may continuously detect whether communications with the one or more remote sensors 150 have resumed. If communications have resumed, the HVAC unit 110 operates according to readings from the one or more remote sensors 150 instead of the return air sensor 125. Alternatively, if all of the one or more remote sensors 150 are still unavailable, the method 200 restarts at 202. In some aspects, the controller 140 faults to the return air temperature sensor when a predetermined threshold number (e.g., 50%, or according to a desired configuration) of remote sensors 150 is unavailable.

By way of example, an element, or any portion of an element, or any combination of elements (e.g., the controller 142 or other components of the HVAC system 100) may be implemented as a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, systems on a chip (SoC), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

Accordingly, in one or more example aspects, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. Storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise a random-access memory (RAM), a read-only memory (ROM), an electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the aforementioned types of computer-readable media, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer. 

1. A system for faulting to a return air sensor integrated within a heating, ventilation, and air conditioning (HVAC) unit, the system comprising: a memory configured to store instructions; and a processor coupled with the memory and configured to execute the instructions, wherein the processor is configured to: transmit a signal to a remote sensor; determine that a return signal is not received from the remote sensor; obtain a temperature reading from the return air sensor; determine whether the temperature reading satisfies a temperature setting stored in the memory; in response to determining that the temperature reading does not satisfy the temperature setting, enable heating or cooling of the HVAC unit until the temperature setting is satisfied; and in response to determining that the temperature reading satisfies the temperature setting, disable heating or cooling of the HVAC unit.
 2. The system of claim 1, wherein the processor is further configured to: determine that the HVAC unit is in an off cycle for a predetermined period of time; circulate air from the HVAC unit into a building by enabling a blower of the HVAC unit; and obtain a temperature reading from the return air sensor.
 3. The system of claim 2, wherein the air is circulated for a predetermined period of time or a predetermined number of cycles.
 4. The system of claim 1, wherein the processor is further configured to: issue a warning to a user of the HVAC unit that communication is lost with the remote sensor in response to an absence of the return signal from the remote sensor.
 5. The system of claim 1, wherein the processor is further configured to: determine that communication is lost with the remote sensor if a return signal is not received after a predetermined amount of time.
 6. The system of claim 5, wherein the predetermined amount of time is substantially equal to thirty seconds.
 7. The system of claim 1, wherein the processor is further configured to: detect that a network to which the HVAC is configured to connect to is unavailable; and use the return air sensor to control the HVAC unit.
 8. The system of claim 1, wherein the processor is further configured to: detect communication has resumed with the remote sensor; and operate the HVAC unit using the remote sensor.
 9. The system of claim 1, wherein the processor is further configured to: enable a blower prior to obtaining the temperature reading from the return air sensor; and wait for a predetermined number of air cycles or a predetermined period of time before obtaining the temperature reading.
 10. The system of claim 1, wherein the processor is further configured to: obtain an outside temperature reading; and offset the temperature reading from the return air sensor based on the outside temperature reading.
 11. The system of claim 1, wherein the return air sensor is located inside a return duct within the HVAC unit.
 12. A method for faulting to a return air sensor integrated within a heating, ventilation, and air conditioning (HVAC) unit, comprising: transmitting a signal from an HVAC unit controller to a remote sensor; determining that a return signal is not received from the remote sensor; obtaining a temperature reading from the return air sensor integrated within the HVAC unit; determining whether the temperature reading satisfies a temperature setting; in response to determining that the temperature reading does not satisfy the temperature setting, enabling heating or cooling of the HVAC unit until the temperature setting is satisfied; and in response to determining that the temperature reading satisfies the temperature setting, disabling heating or cooling of the HVAC unit.
 13. The method of claim 12, further comprising: determining that the HVAC unit is in an off cycle for a predetermined period of time; circulating air from the HVAC unit into a building by enabling a blower of the HVAC unit; and obtaining a temperature reading from the return air sensor.
 14. The method of claim 13, wherein the air is circulated for a predetermined period of time or a predetermined number of cycles.
 15. The method of claim 12, further comprising: issuing a warning to a user of the HVAC unit that communication is lost with the remote sensor in response to an absence of the return signal from the remote sensor.
 16. The method of claim 12, further comprising: determining that communication is lost with the remote sensor if a return signal is not received after a predetermined amount of time.
 17. The method of claim 16, wherein the predetermined amount of time is substantially equal to thirty seconds.
 18. The method of claim 12, further comprising: detecting that a network to which the HVAC is configured to connect to is unavailable; and using the return air sensor to control the HVAC unit.
 19. The method of claim 12, further comprising: detecting communication has resumed with the remote sensor; and operating the HVAC unit using the remote sensor.
 20. The method of claim 12, further comprising: enabling a blower prior to obtaining the temperature reading from the return air sensor; and waiting for a predetermined number of air cycles or a predetermined period of time before obtaining the temperature reading.
 21. The method of claim 12, further comprising: obtaining an outside temperature reading; and offsetting the temperature reading from the return air sensor based on the outside temperature reading.
 22. The method of claim 12, wherein the return air sensor is located inside a return duct within the HVAC unit.
 23. A non-transitory computer-readable medium storing instructions that, when executed by a processor, cause the processor to fault to a return air sensor integrated within a heating, ventilation, and air conditioning (HVAC) unit, comprising: transmitting a signal from an HVAC unit controller to a remote sensor; determining that a return signal is not received from the remote sensor; obtaining a temperature reading from the return air sensor; determining whether the temperature reading satisfies a temperature setting; in response to determining that the temperature reading does not satisfy the temperature setting, enabling heating or cooling of the HVAC unit until the temperature setting is satisfied; and in response to determining that the temperature reading satisfies the temperature setting, disabling heating or cooling of the HVAC unit. 